34277-57-1Relevant academic research and scientific papers
Triethylamine Hydroiodide as a Bifunctional Catalyst for the Solvent-Free Synthesis of 2-Oxazolidinones
Nishiyori, Ryuichi,Okuno, Ken,Shirakawa, Seiji
, p. 4937 - 4941 (2020)
Among the wide variety of heterocycles, 2-oxazolidinones are recognized as some of the most important heterocyclic compounds in medicinal chemistry. Therefore, the development of a practical method for their synthesis would be an important development. He
Microwave-Assisted Electrostatically Enhanced Phenol-Catalyzed Synthesis of Oxazolidinones
Rostami, Ali,Ebrahimi, Amirhossein,Sakhaee, Nader,Golmohammadi, Farhad,Al-Harrasi, Ahmed
, p. 40 - 55 (2021/10/20)
An electrostatically enhanced phenol is utilized as a straightforward, sustainable, and potent one-component organocatalyst for the atom-economic transformation of epoxides to oxazolidinones under microwave irradiation. Integrating a positively charged center into phenols over a modular one-step preparation gives rise to a bifunctional system with improved acidity and activity, competent in rapid assembly of epoxides and isocyanates under microwave irradiation in a short reaction time (20-60 min). A careful assessment of the efficacy of various positively charged phenols and anilines and the impact of several factors, such as catalyst loading, temperature, and the kind of nucleophile, on catalytic reactivity were examined. Under neat conditions, this one-component catalytic platform was exploited to prepare more than 40 examples of oxazolidinones from a variety of aryl- and alkyl-substituted epoxides and isocyanates within minutes, where up to 96% yield and high degree of selectivity were attained. DFT calculations to achieve reaction barriers for different catalytic routes were conducted to provide mechanistic understanding and corroborated the experimental findings in which concurrent epoxide ring-opening and isocyanate incorporation were proposed.
Squaramide–Quaternary Ammonium Salt as an Effective Binary Organocatalytic System for Oxazolidinone Synthesis from Isocyanates and Epoxides
Rostami, Ali,Ebrahimi, Amirhossein,Husband, John,Anwar, Muhammad Usman,Csuk, Rene,Al-Harrasi, Ahmed
, p. 1881 - 1895 (2020/03/13)
Squaramide–quaternary ammonium salt is illustrated as a simple, tunable, and competent metal-free binary catalytic platform for the atom-economic conversion of epoxides and isocyanates into oxazolidinones. Although, various metal catalysts have been employed for the title reaction, application of organocatalysis is scarce. At first, a rational survey of catalytic activity of several air-stable and architecturally distinct squaramides was undertaken. Thereafter, the impact on catalytic capability of different parameters, such as temperature, catalyst loading, and nature of nucleophiles, was examined. This binary organocatalytic system for the oxazolidinone synthesis, composed of a squaramide entity along with a suitable halide anion, was applied to the challenging conversion of a plethora of alkyl- and aryl-substituted epoxides– including disubstituted and enantioenriched ones– and isocyanates into the corresponding oxazolidinones in high-to-excellent yields. The time-dependent formation of oxazolidinone from epoxide and isocyanate was monitored by FTIR-ATR and 1H NMR spectroscopy and the scalability of this process was also described. In light of 1H NMR experiment, a hydrogen-bonding/anion-binding mechanism was proposed wherein the nucleophilic ring-opening operation, and oxo- and carbamate-anions stabilization occur cooperatively towards isocyanate fixation.
Chemistry of Sulfonyl Isocyanates and Sulfonyl Isothiocyanates. XI. Cyclizations with Epoxides
McFarland, J. W.,Beaulieu, J. J.,Arrey, L. N.,Frey, L. M.
, p. 1431 - 1434 (2007/10/02)
4-Toluenesulfonyl isocyanate cyclized with 1,2-epoxy-3-phenoxypropane and 2,3-epoxypropyl 4-methoxyphenyl ether, respectively, to give 3-(4-toluenesulfonyl)-5-phenoxymethylene-2-oxazolidone (I) and 3-(4-toluenesulfonyl)-5-(4-methoxyphenoxymethylene)-2-oxazolidone (II).Compounds I and II were hydrolyzed in 2 M sodium hydroxide solution to the corresponding uncyclized hydroxy amides, VII and VIII.Compound I was remarkably stable toward 6M hydrochloric acid and amines.Styrene oxide, 1,2-epoxybutane, 3-chloro-1,2-epoxypropane, and 1-methoxy-2-methylpropylene oxide reacted with the isocyanate to afford 3-(4-toluenesulfonyl)-4-phenyl-2-oxazolidone (III), 3-(4-toluenesulfonyl)-4-ethyl-2-oxazolidone (IV), 3-(4-toluenesulfonyl)-5-chloromethyl-2-oxazolidone (V), and 3-(4-toluenesulfonyl)-4,4-dimethyl-5-methoxy-2-oxazolidone (VI), respectively.The yield of VI was constant over a temperature range of 25-90 deg.
